Dynamic seating device

ABSTRACT

The present invention relates to a dynamic seating device with a seat plate ( 1 ), which is mounted by means of a bearing head ( 5 ) on an under-frame with a height-adjustable column ( 14 ) or on a bearing surface. In order to automatically ensure natural movements of the user at the same time with free mobility, according to the invention it is proposed that the seat plate ( 1 ) comprises a recess ( 8 ) arranged in its centre, becoming larger from its top side towards its lower side, that a bush ( 19 ) is passed from below and secured through the recess ( 8 ) in the seat plate ( 1 ), that the bush ( 19 ) rests on the bearing head ( 5 ) of a support pin ( 6 ), wherein the bearing head ( 5 ) is shaped spherically or hemispherically, so that a common rotating and swivelling point arises above the seat plate ( 1 ).

The present invention relates to a dynamic seating device with a seat plate, which is tiltably and rotatably mounted by means of a bearing head on an under-frame with a height-adjustable column or on a bearing surface.

“Sitting as stress” is the title of a book by the SVSS author team (Verlag pmsi Holdings Deutschland GmbH, 1993, recommended by the Federal Association of German Back Schools). It explains in 200 pages that correct sitting is not a rigid posture, but requires constant mobility. Since these unrestricted movements are not attainable when sitting on normal seats, various changes of sitting postures, which humans must consciously take up in alternation, are suggested in this book. It is illustrated how difficult it is in everyday life and at the workplace to move sitting in a body-conformal way. Some of the recommended sitting postures however do not permit desk work or other activities such as piano playing among other things to be performed. To some extent work-preventing postures are suggested, which although able to produce physical sensitisation processes, are unfit for work and everyday tasks over longer periods. These shortcomings in sitting and movement however can be prevented by a suitable seating device.

A stool, which through cylindrical segments placed one above the other allow movement of the seat face over two horizontal axes offset by 90°, is known as a seating device, which should improve sitting from a health point of view, from German Patent DE 201 10 832 U1. As a result of the distance between the two axes there is a difference between pitch- and lateral tilting movement. Overall, both fulcrums of the coccyx are spaced too far apart to allow physiological optimum and homogeneous transmission of movement to take place.

A further mobile seating device is described in German Patent DE 295 16 794 U1, whose main feature however is a flexible seat with a resetting force and therefore does not meet the demands made here.

In addition from French Patent FR 27 94 349 A1 it is known how to mount a seat plate on a hemispherical bearing head so that it can tilt and rotate, wherein the hemispherical bearing head is mounted in a spherical recess on the lower side of the seat plate.

It is common to the dynamic seating devices described above that the user, with the structure of the known seating device selected in each case, is forced into unnatural and over longer duration unpleasant movements. For work and everyday tasks these seating devices are therefore only suitable to a limited extent.

On the basis of the state of the art described above the object of the present invention is to create a seating device of the kind initially specified, which automatically allows natural movements of the user at the same time with free mobility.

The object stated above is achieved in accordance with a first teaching of the present invention by the fact that the seat plate comprises a recess arranged in its centre, becoming larger from its top side towards its lower side, that a base plate with a dome-shaped protuberance is secured in the centre of the seat plate on its top side, that the base plate rests on the bearing head of a support pin, wherein the bearing head is shaped hemispherically and that the support pin is rigidly connected to the column or to a plate forming the bearing surface and protrudes through the recess through the seat plate, so that the seat plate can tilt in all directions and rotate without hindrance.

Furthermore, the object stated is achieved in accordance with a second teaching of the present invention by the fact that a conical bush, which is secured to the lower side of the seat plate, protrudes through a central hole in the seat plate, that the bush rests on the bearing head of a support pin, wherein the bearing head is shaped spherically, and that the support pin is rigidly connected to the column or to a plate forming the bearing surface, so that the seat plate can tilt in all directions and rotate without hindrance.

Finally, the object stated is achieved in accordance with a third teaching of the present invention by the fact that the seat plate comprises a recess arranged in its centre, becoming larger from its top side towards its lower side, that a conical metal cap, reduced in diameter from bottom to top, is passed from below through the recess in the seat plate and secured, and that the metal cap rests on the bearing head of a support pin and forms the bush, wherein the bearing head is shaped hemispherically so that a common rotating and swivelling point arises above the seat plate.

The present invention therefore consists of a dynamic seating device, in which to achieve natural movements of the user at the same time with free mobility, according to the invention it is proposed that the seat plate has a central recess running conically from top to bottom with a bush inserted from below, which rests on the spherical or hemispherical bearing head of a support pin, so that a common rotating and swivelling point arises above the seat plate, not under it.

This invention concerns a seating device, which prevents posture injuries particularly within the extended spinal column region, by permitting free mobility and simultaneously physiologically centred sitting through a common rotating and swivelling point above the seat plate. In addition, body regions which have already become stiff can be rehabilitated thereby. This seating device can be employed both for daily use and for therapeutic purposes.

The seating device can offer possibilities to again achieve a natural upright posture, which can no longer be taken up due to reduced work and everyday tasks, and to avoid damage to the body—particularly to the spinal column. The seating device should create possibilities for the individual to recover an already lost sensitivity for dealing naturally with his/her own body as well as offering movement possibilities, which allow total freedom for constant movement when sitting. Although humans sit, they must be in continuous movement and in constant play with the equilibrium if the natural oscillations of the body are to be continually allowed and tensions are not to build up in any way. Rigid sitting should be avoided, so that constant play with the equilibrium can take place and many natural bodily functions are not lost and are regained, respectively.

In order to achieve this, a seat face must allow free tilting movements to all sides without disturbing resetting forces of the seat and the common rotating and swivelling point of the seat plate must lie directly above so that a natural extension of the spinal column beyond the coccyx is provided and thus constant transmission of movement can take place within the entire body.

Further arrangements of the invention are indicated in the dependent claims and are elucidated in detail below in connection with the explanation given with reference to a drawing of several exemplary embodiments. In the drawing there are shown in each case schematically, in cross section:

FIG. 1 a first exemplary embodiment of a seating device according to the invention with a height-adjustable column;

FIG. 2 a second exemplary embodiment of a seating device according to the invention for placing on any sub-base;

FIG. 3 a third exemplary embodiment of a seating device according to the invention with a height-adjustable column;

FIG. 4 a fourth exemplary embodiment of a seating device according to the invention for placing on any sub-base;

FIG. 5 a fifth exemplary embodiment of a seating device according to the invention with a height-adjustable column; and

FIG. 6 in sectional view a mounting in the case of a sixth exemplary embodiment of a seating device according to the invention.

In accordance with FIG. 1 a seat plate 1, preferably made from wood, is rigidly connected by several bolt connections 4 to a base plate 7, which through a dome shaped protuberance forms the upper shell of a slide bearing. A thin foam-material sheet 2 glued with the seat plate 1 covers this base plate 7 and ensures a soft, anti-slip seat face. The centre of the seat plate is provided with a recess 8, so that the dome of the base plate 7 can rest on a hemispherical plastic part 5 pressed in a support pin 6 and the conjoined seat plate 1 could tilt at least +/−20° in all directions. In order to keep the friction in this bearing to a minimum and nevertheless achieve the necessary stability, steel was selected as the material together with its diameter of 14 mm for the support pin 6. The support pin 6 is rigidly connected to a height-adjustable column 14 by adhesive, a dowel pin 15 or a screw. The column 14 is vertically adjustable and can be fixed in an under-frame consisting of a plate 16 and at least three feet 17. For example, the column 14 can be constructed as a spindle and engage in a screw thread of the plate 16 in the manner of a piano stool, so that vertical adjustment can take place by rotating the plate 13. Seat plate 1 and a round plate 13 rigidly connected to the column 14 form the stop for limiting the tilting movement. The plate 13 at the same time prevents the column 14 from being torn out, if this should be made of wood. In order to prevent the seat plate 1 from lifting off when being transported, a spring washer 11 is pushed onto the support pin 6, and a washer 12 mounted between spring washer 11 and plate 3 is dimensioned so that it does not obstruct the tilting movement of the seat plate 1 and also does not pass through the central hole of the plate 3, which is rigidly connected to the lower side of the seat plate 1.

In FIG. 2 an embodiment without vertical adjustment is illustrated. Here the under-frame is replaced by a plate 10, so that the seating device can be placed on any sub-bases suitable for seating.

A seat plate 1, preferably made from wood, in accordance with FIG. 3 is provided with a central conical hole, through which the conical bush 19 protrudes and is rigidly connected to the lower side of the seat plate 1 by fastening elements 4. As the lower part of the slide bearing the support pin 6 is connected at its tip to a spherical bearing head 5. A cap 20 made from self-lubricating plastic lies between them. As a result of this construction the bearing point is able to lie above the seat plate 1 and the latter can tilt approximately ±20° in all directions. To prevent the seat plate 1 lifting off from the support pin 6 a conical bracket 21, through which the bearing head 5 on its top side does not pass, is secured together with the conical bush 19 on the lower side of the seat plate 1. A foam-material sheet 2 glued to the seat plate 1 covers the conical bush 19 and ensures a soft, anti-slip seat face. The support pin 6 is rigidly connected to a height-adjustable column 14 by adhesive, a dowel pin 15 or a screw thread 22. The column 14 is vertically adjustable and can be locked in an under-frame consisting of a plate 16 and at least three feet 17. For example, the column 14 can be constructed as a spindle and engage in a screw thread of the plate 16 in the manner of a piano stool, so that vertical adjustment can take place by rotating the plate 13. Seat plate 1 and a round plate 13 rigidly connected to the column 14 form the stop for limiting the tilting movement. The plate 13 at the same time prevents the column 14 from being torn out, if this should be made of wood.

In FIG. 4 an embodiment without vertical adjustment is illustrated. Here the under-frame is replaced by a plate 10, so that the seating device can be placed on any sub-bases suitable for seating.

In accordance with FIG. 5 a conical bush 19 provided with an edge 24 at the bottom is secured from below to the seat plate 1 through a recess 8 in the seat plate 1, which preferably consists of wood. A foam-material sheet 2 glued to the seat plate 1 covers the seat plate 1 and the bush 19 and ensures a soft, anti-slip seat face. The support pin 6 is rigidly connected to a height-adjustable column 14 by adhesive, a dowel pin or a screw thread 22 and forms the lower part of the bearing, so that the seat plate 1 mounted with the bush 19 can tilt in all directions as far as the angle of the cone of the bush 19 permits and allows it rotate without hindrance. In order to keep the friction in this bearing to a minimum and nevertheless achieve the necessary stability, metal was selected as the material for the support pin 6 and its head 5 consists of a hemispherical plastic part, which is held in position by a locking pin 23. The column 14 is vertically adjustable and can be fixed in an under-frame consisting of a plate 16 and at least three feet 17. For example, the column 14 can be constructed as a spindle and engage in a screw thread of the plate 16 in the way of a piano stool, so that the vertical adjustment can take place by rotating the plate 13, which is rigidly connected to the column 14. Seat plate 1 and the round plate 13 form the stop for limiting the tilting movement. The plate 13 at the same time prevents the column 14 from being torn out, if this should be made of wood. In order to prevent the seat plate 1 from lifting off, the bush 19 is pressed circularly at its constriction 25, after being placed on the support pin 6.

A further arrangement for preventing the seat plate 1 from lifting off is illustrated in FIG. 6. A hollow cone 26, which consists of two parts and extends to the bearing head 5, is inserted into the bush 19 after being placed on the support pin 6 and is held with a circular metal plate 27, which is secured together with the bush 19 to the lower side of the seat plate 1. The hollow cone 26 can also consist of only one part if the diameter of the shank of the support pin 6 is less than its bearing head.

REFERENCE NUMERAL LIST

-   1 seat plate -   2 flexible material or upholstery -   3 plate -   4 fastening element -   5 bearing head -   6 support pin -   7 base plate -   8 recess -   9 fastening element -   10 plate -   11 pressed-on spring washer -   12 washer mounted on the support pin -   13 plate -   14 column -   15 dowel pin -   16 plate -   17 feet -   18 recess -   19 bush -   20 cap -   21 conical bracket -   22 screw thread -   23 pin -   24 edge of the bush -   25 constriction -   26 hollow cone -   27 circular metal plate 

1. Dynamic seating device with a seat plate (1), which is mounted by means of a bearing head (5) on an underframe with a height-adjustable column (14) or on a bearing surface, characterized in that the seat plate (1) comprises a recess (8) arranged in its centre, becoming larger from its top side towards its lower side, that a base plate (7) with a dome-shaped protuberance is secured in the centre of the seat plate (1) on its top side, that the base plate (7) rests on the bearing head (5) of a support pin (6), wherein the bearing head (5) is shaped hemi-spherically, and that the support pin (6) is rigidly connected to the column (14) or to a plate (10) forming the bearing surface and protrudes through the recess (8) through the seat plate (1), so that the seat plate (1) can tilt in all directions and rotate without hindrance.
 2. Dynamic seating device according to claim 1, characterized in that the support pin (6) consists of a metal tube, into whose upper end a bearing head (5) made from self-lubricating plastic is pressed.
 3. Dynamic seating device according to claim 1, characterized in that the support pin (6) and the bearing head (5) are integral.
 4. Dynamic seating device according to claim 2, characterized in that the radius of the dome-shaped protuberance of the base plate (7) and the radius of the bearing head (5) are less than 7 mm.
 5. Dynamic seating device according to claim 1, characterized in that a plate (13) is provided, which is arranged under the seat plate (1) and is connected to the column (14) or to the plate (10) in such a manner that the tilting movement of the seat plate (1) is restricted.
 6. Dynamic seating device according to claim 1, characterized in that a spring washer (11), pressed onto the support pin (6), a washer (12) which is mounted underneath the spring washer (11) on the support pin (6) and whose inside diameter is much larger than the support pin (6) so that this can tilt by at least 20° relative to the washer (12), and a plate (3) which is arranged underneath the washer (12) on the support pin (6) and rigidly connected to the lower side of the seat plate (1) and whose central hole is so large that the tilting of the seat plate (1) is not impaired and the washer (12) cannot fall through, are provided so that the seat plate (1) is prevented from lifting off.
 7. Dynamic seating device according to claim 6, characterized in that a recess (18) is provided on the lower side of the seat plate (1) in such a manner that a horizontal movement of the washer (12) parallel to the plate (3) is allowed.
 8. Dynamic seating device according to claim 6, characterized in that a spacer is provided between the plate (3) and the lower side of the seat plate (1) in such a manner that the movement of the washer (12) parallel to the plate (3) is allowed in all directions.
 9. Dynamic seating device according to claim 5, characterized in that the column (14) and the plate (13) are made of wood, wherein the plate (13) is firmly glued with the column (14).
 10. Dynamic seating device according to claim 1, characterized in that the surface of the seat plate (1) is upholstered with flexible material (2) and lined with a covering material or leather.
 11. Dynamic seating device with a seat plate (1), which is mounted by means of a bearing head (5) on an underframe with a height-adjustable column (14) or on a bearing surface, characterized in that a conical bush (19) which is secured to the lower side of the seat plate (1), protrudes through a central hole in the seat plate (1), that the bush (19) rests on the bearing head (5) of a support pin (6), wherein the bearing head (5) is shaped spherically, and that the support pin (6) is rigidly connected to the column (14) or to a plate (10) forming the bearing surface, so that the seat plate (1) can tilt in all directions and rotate without hindrance.
 12. Dynamic seating device according to claim 11, characterized in that a cap (20) made from plastic is arranged between the conical bush (19) and the spherical bearing head (5) of the support pin (6).
 13. Dynamic seating device according to claim 11, characterized in that a conical bracket (21) is provided, whose upper opening is smaller than the bearing head (5) and which is secured together with the bush (19) to the lower side of the seat plate (1), in such a manner that when the seat plate (1) is raised, it is prevented from lifting off.
 14. Dynamic seating device according to claim 11, characterized in that a constriction (25) of the bush (19) is provided underneath the bearing head (5), in such a manner that when the seat plate (1) is raised, it is prevented from lifting off.
 15. Dynamic seating device with a seat plate (1), which is mounted by means of a bearing head (5) on an underframe with a height-adjustable column (14) or on a bearing surface, characterized in that the seat plate (1) comprises a recess (8) arranged in its centre, becoming larger from its top side towards its lower side, that a conical metal cap, reduced in diameter from bottom to top, is passed from below through the recess (8) in the seat plate (1) and secured, and that the metal cap rests on the bearing head (5) of a support pin (6) and forms the bush (19), wherein the bearing head (5) is shaped hemispherically, so that a common rotating and swivelling point arises above the seat plate (1).
 16. Dynamic seating device according to claim 15, characterized in that the conical bush (19) is provided at the bottom with an edge (25), with which the bush (19) can be secured from below to the seat plate (1).
 17. Dynamic seating device according to claim 15, characterized in that the support pin (6) in the lower part is shaped cylindrically, in the part adjoining thereto as a truncated cone and in the top part hemispherically and in the centre is provided with a vertical pin (23), which seats and fixes the bearing head (5) made from self-lubricating plastic through its hole.
 18. Dynamic seating device according to claim 15, characterized in that the conical bush (19) after being placed on the support pin (6) is provided with a constriction (25), which prevents the bush (19) from being lifted off the support pin (6).
 19. Dynamic seating device according to claim 15, characterized in that a hollow, split truncated cone (26) fitting into the bush (19) is provided, whose upper opening is smaller than the diameter of the spherical bearing head (5) of the support pin (6) and which is secured together with the edge (24) of the bush (19) to the lower side of the seat plate (1) by means of a washer (27) in such a manner that after the conical bush (19) has been placed on the support pin (6) the seat plate (1) is prevented from lifting off.
 20. Dynamic seating device according to claim 15, characterized in that the lower cylindrical part of the support pin (6) is provided with a screw thread (22) and engages into a concentric hole of the column (14).
 21. Dynamic seating device according to claim 15, characterized in that the seat plate (1) is provided with upholstery (2). 